Automatic valve and system



2 Sheets-Sheet l INVENTOR.'

ATTHNE'Y H. E. THORNHILL AUTOMATIC VALVE AND SYSTEM HoMER E. THoRNHxLL July4 27, 1954 Filed March 2, 1949 July 27, 1954 H. E. THORNHILL AUTOMATIC VALVE AND SYSTEM 2 Sheets-Sheet 2 Filed March 2, 1949 XTMS ATTORNEY Patented July 27, 1954 yUNITED STATE ATENT OFFICE Thornhill-Graver Company,

Inc., Houston,

Tex., a corporation of Texas Application March 2, 1949, Serial No. 79,123

25 Claims.

This invention pertains to automatic valves, and more particularly to automatic shut-off .valves for petroleum pipe lines.

Usually a petroleum oil and gas well is located at a considerabledistance from the collection and storage tank to which it is connected.

The vconnecting pipe may run under, on or `over ground, Water kor roads, in fact it may chance to be most anywhere. 4It is therefore constantly subject to breakage from passage thereover of ships, tractors, trucks, or by` snagging anchors,xplows, or chains. Inaddition, it may burst due` to excessive well pressure. In anyevent, a break will constitute a hazard at the pointv of breakage due to the inflammable and explosive nature of thesubstance. In addition, there is considerable economic waste due to the loss .of oil and gas through the break.

t is the .principal object of Vthis invention to provide a valve and control system or auto- .rnatically closing in a well either in case oi excessive pipe line ,pressure which might cause the pipe to break or in case of an actual break due to any cause. v

It is a further object of the invention to provide a valve and control system of the aforesaid type which will keep the well closed in once it has `beenclosed in until the valve systernV is manually reopened. Y

It is `another'object of the invention to provide such a valve and control system which will automatically indicate the position of the valve, that is, whether open or shut.

K Another object of the invention `is to provide a valve and control system therefor which :1

- mum of time, elort and expense.

A further object of the invention'is to provide such a valve and control system which will be, i... simple and reliable in operation.

Another object of the invention is to provide 'such a valve and control system which will be inexpensive to manufacture and economical to operate.

A further object of the invention is to provide such a valve and control system that will occupy a minimum amount of space.

Briefly, the invention comprisesia valve element which can replace the valve element of the fil) 2 usual adjustable choke or wing valve on the Christmas tree just upstream from the positive choke. The valve stem passes through a packing gland and A,is connected to a large piston traveling in a large cylinder and beyond that to a small piston traveling in a small cylinder. The far end of the small cylinder isalways connected to the upstream side of the valve and exerts a pressure tending to close the valve. The large cylinder, at a point close to the end thereof nearest the valve, is always connected through a small choke to the pipe line downstream of the valve and positive choke. Normally the Valve is open and the areas of the` two pistons are so related to the upstream and downstream pressures that the valve is held open. Upon a drop in downstream pressure, however, the valve will be closed. As the valve approaches closed position an auxiliary valve in an atmosphericrexhaust line leading to another port connected to the extreme near end of the large cylinder will open, thus further dropping the pressure in the large cylinder. Near the end of the movement the large piston itself blocks oli the port leading to the downstream line so that even if the pressure should return to normal thevalve would stay closed. Because of this construction, whenever the valve is closed the pressure in the large cylinder is atmospheric.

The extreme near end of the large cylinder is also connected through a manually operated three-way valve to another atmospheric exhaust line.- The latter is normally closed by a pop valve set'to open-at a predetermined pressure. Upon an excessive increase in the downstream pressurethe pop valve will open causing a drop in pressure in the large cylinder and the main valvewill close ythe same as though there'were a drop in the downstream pressure. The small choke inthe line-from the pipe line to the large cylinder insures-thattherewill be a sufficientldrop-in pressurein the'large Vcylinder Yunder these conditions.

A *hand operatedI bleeder -valve controls a branch line from the linecontrolled bythe pop valve; Ii it isY desired to'close themain valve the Yhleeder valvefis openedywhichfdrops the pressure intheflarge cylinder the same as if the pop `valve hadv opened.

' if --it is vdesired toppen the main valve, which mustalwaysbe done-manually, the above-mentionedthree-'wayvalve is turned so as to connect YtheY large cylinder to a line from the upstream' side of the Vmain valve instead of the pop valve controlled'at'mospheric exhaustline. A'This bringsY the Y pressure in the large cylinder up nearly to that in the small cylinder, the other lines leading from the large cylinder being small enough to serve as chokes, so that the force of the small cylinder is overbalanced and the valve opened. Returning the three-way valve to its previous position makes the system responsive again, in which condition any excessive drop in pressure in the large cylinder will cause it to close. Such a drop may occur in any of three ways: manual opening of the bleeder valve, automatic opening of the pop Valve on excessive pressure, or breakage of the downstream line causing an excessive drop in pressure. A pressure gauge is also connected to the exhaust line leading to the pop valve from the large cylinder. If the gauge shows that there is pressure in the cylinder, it indicates the main valve is open. If the gauge shows atmospheric pressure, the main valve is closed.

One of the principal advantages of the invention lies in the fact that no springs are used, except perhaps on the pop valve, and even here the spring can be eliminated by substituting a weight. Springs are very undesirable in a valve of this sort due to the presence of sand, shale, dust, paraiin, hydrogen and other substances in the crude petroleum. Hydrogen absorption embrittles the springs and causes them to break. Sand and other substances are apt to cause the springs to stick.

Another advantage lies in the fact that only a small amount of gas is used to operate the valve. There is no continuous ow of gas and therefore little likelihood of freezing.

lOther objects and advantages of the invention will appear from the following detailed description of a preferred embodiment thereof in which:

Figure 1 is a section taken along the axis of the valve; and

Figures 2, 3, and 4 are schematic drawings of the control system showing the valve open and responsive, closed, and manually opened, respectively.

Figures 5, 6, and 7 show a four-way valve suitable for use in the system.

Referring now to Figure l, the valve comprises a valve body I having a threaded inlet 2 adapted to be connected to a side arm of a Christmas tree manifold. The valve body also has a flanged outlet .t adapted to be connected to a positive choke from which leads the pipe line going to the storage tank. The valve body is in the shape of a T, the inlet 2 being at the base of the T. and the outlet 3 beine in one of the arms of the T. Through the other arm of the T projects a valve stem i on which is mounted the valve 5 which cooperates with a removable valve seat 6 threadedly supported within the o-utlet 3. The valve stem l is slidably supported within the center of the arm of the T opposite the outlet by means of a flanged valve bonnet '1. The valve bonnet is sealed to the end of the valve body by means of a steel ring gasket 8 and is secured thereto by means of a fast coupling 9.

The valve bonnet is provided with two cylindrical bearings lil and i! for supporting the c vlindrical valve stem A.. Within. each of the two an nular grooves i2 i3 Within the bearings Hi and i! there mounted a neoprene O ring such as that .shown at lll disposed between a pair of leather non-extrusion rings such as that shocmv at i5. These form pair of spaced. sliding seals between the valve stem 4 and the valve bonnet 2'.

An actuating cylinder 2li is connected to the outer end of the valve bonnet 1 by means of screw thread 2i and is sealed thereto with a neoprene O ring 22. The cylinder is provided with a large bore 23 within which slides cylindrical piston 2i connected to the outer end of the valve stem il. Within an annular groove 25 on the periphery of the piston 2li is disposed a neoprene O ring 2t. The O ring is placed between two leather noneXtrusion rings, such as that shown in 2l. These rings form a seal between the piston and the cylinder walls. Similar O rings and non-extrusion rings placed in a second annular groove 28 in the periphery of the piston 24 provide a second sliding seal between the piston and cylinder walls.

A small piston 39 is threadedly connected at 3l within an apertru'e in the end of piston 24 opposite `the valve stem and is sealed thereto by means of neoprene O ring 32. Cylindrical piston 3i! travels within cylindrical bore 33 in a small cylinder 3l! telescoped within counterbore 35 in the end of cylinder 2i! farthest from the valve bonnet. Cylinder 34 is held in place in the end of cylinder Zi] by means of a snap ring 36 placed over the reduced end 31 of cylinder 34 and eX- panded into annular groove 33 within the end of counterbore 35. Cylinder 34 is sealed to `cylinder 2li by means of O ring 39. An O ring and two leather non-extrusion rings placed in annular groove within the bore 33 iof cylinder 3d provide a sliding seal between the small piston 3! and the small `cylinder walls 33. This construction makes it possible to adapt the valve and. control system to a particular set of operating lpressures corresponding to a particular well and pipe line by changing the size of the highpressure cylinder without having to change the rest of the valve control mechanism. It is only necessary to select the desired size cylinder Bi and lock it in place in the end of cylinder 2Q and select a piston 30 to fit the `cylinder 3ft and screw it in place in the end of piston 24.

The valve stem 4 `is provided with radial and axial bores 50 and `5! and piston 3B is yprovided with an axial bore 52. These, together with space 53 between the socket in large piston 24 and the screw plug end of small piston 39, form a continuous passage from the up-stream or highpressure portion of the interior of the valve body l to the interior of the small or high-pressure cylinder 3d. A port -54 in the end of the cylinder 2li and a screw socket 55 therein provide a passage from the interior of the small or high-pres" sure cylinder to the manually operated threeway valve. These internal passages through the valve eliminate the necessity for tapping into the Christmas tree in order to connect to the highpressure iiuid in the well which is used for urging the valve to `closed position. It also reduces to a minimum the amount of high-pressure tubing needed for the control system.

A radial port 5l? and a longitudinal passage Si connect the interior of the large or lowpressure cylinder 2li to a screw socket 52 in the end of the cylinder body 2li adapted t-o receive a small choke plug. The other side of the choke plug will be connected through a control line to the pipe line on the dofwn-sJream or lowmpressure side of the positive choke. If desired the choke may be a small hole drilled in `the body rather than being added as an accessory or the port 6e and passage El may be Ysmall enough to serve as a choke themselves. However, the removable choke makes the apparatus more adaptable to changed operating pressures.

As shown in the drawings, when the valve is in the closed position the piston 2li blocks off mosphere.

'the end of passage '60, thereby Ipreventing the low-pressure fluid from the -pipe line getting between the piston`24 and the end of the cylinder 20 nearest the valve. When the valve is opened a small amount of port EEl) is uncovered and admits low--pressure uid to this space so as to urge the valve towards its open position. Thus port 60 and piston 24 Iconstitute a secondary valve means for controlling uid flow in the low-pressure control line. Under normal conditions the force exerted by .this low-pressure fluid on pis- 'ton 24 is greater than the force exerted by the high-pressure iiuid on the end of piston 3Q, so that the main valve stays open.

Radial passage and longitudinal passages 1I and 12 in the walls of the cylinder 20 provide a connection from the operating space in the 'low-pressure cylinder between piston 2d and the end of the cylinder nearest the valve to a screw 'socket 15 in the end of cylinder body 20. A screw plug in the socket will connect these passages to a control pipe leading to the three-way valve. In the normal position of the three-way valve, the ycontrol pipe will in turn be connected to another control pipe leading .to the manual bleed valve, the pressure gauge, and the excess-pressure pop valve. The pop valve is constructed to reclose at `a lower pressure than that at which it opens. If the bleed valve should be manually opened, or if the pop valv-e should open because of excessive pressure in the pipe line downstream from 'the positive choke, the pressure in the operating space of the low-pressure cylinder will fall, permitting the. valve to be closed by the high-pressure fluid in the small cylinder. The same thing would occur if there should be a fall in pressure in the Ipipe line due to breakage or other cause. The pressure gauge indicates the position of the valve.

A radial port S0, a longitudinal bcretll, and a radial port 83 connect the operating space of the low-pressure cylinder to an annul-ar space 84 within the valve bonnet 7 between the bearings i0 and =i I. A passage 85 connects space S4 to at- When the valve yis in its normal or open position, the end of por-t 83 will be blocked oi by bearing Il. Whenever the valve moves a short distance toward its closed position, due to any of the previously mentioned causes, the port 83 will be opened, allowing the low-pressure fluid r actuated by the main valve referred to in the,

brief introductory des-cription of the invention; IIhel port 8i! is vdrilled to the proper size to prevent'the low-pressure fluid from exhausting too fast. This keeps the valve from slamming shut.

If desired a removable choke plug could be usedV here toV adapt the apparatus to different operating pressures.

Beca-use of the fact that the large cylinderZ also houses the small-cylinder 34, there is a possibility that despite the seals between the cylin- Y ders yand the pistons operating therein fluid under V'pressure may leak into the space between the large piston Zllfand the -innerV end ofthe small cylinder 34. Such an accumulation on the backside of piston 24 would render the system and valve inoperative. 'Toprevent this from happen- The end of the passage is ab 6 ing, the cylinder 20 is provided'with one or more vents such :as the radial bore 81.

Assuming the valve to be in the closed position as shown inthe drawings, if it desired to open the valve this can be accomplished by connecting the pipe from the socket with the control pipe from the socket 13. This can be done by changing the position of the lthree-way valve.

' This admits high-pressure uid to the operating space of the low-pressure cylinder, thereby overcoming the force in the high-pressure `cylinder tending to keep the valve closed. The exhaust passage 8i from the low-pressure cylinder to atmosphere is of sufficiently small size so that enough pressure can build up in the low-pressure cylinder under these conditions to open the valve. After the valve has been opened the three-way valve is returned to its Ioriginal position, in which the control pipe connected to the socket 55 is closed olf and. the control pipe connected to the socket 73 is in communication with the pop valve.

Referring now to Figure 2, there is shown a schematic representation of a well and pipe line system, together with the automatic shut-off valve and the -control system'therefor. The main pipe line system is shown in heavy lines. The control lines leading to the shut-off valve are shown in light lines. rIhe well l is connected through master Valve lili of the Christmas tree` to yautomatic shut-ofi valve 462. 'Ihe outlet of shut-oir valve ll2 leads to positive choke |03, which, in turn, is connected to the pipe line H05 leading to a suitable separator and thence to storage tank H35.

The control system comprises high-pressure control line IE5 leading from the high-pressure side of the positive choke to the high-pressure cylinder 34. (In the construction shown 4in Figure 1, the high-pressure line it is constituted by the -passages 5i), 15! and 52 through the valve stem and pistons.) The low-pressure cylinder 2! is connected through a lsmall choke |01 an-d lowpressure control line m3 tothe low-pressure side of the positive choke 55.33. The extreme end of low-pressure cylinder 2@ is connected to atmosphere through auxiliary valve 169. (In the construction shown in Figure l the auxiliary valve 169 is constituted by the port 83 in .the va'lve stem and the bearing l l for the valve stem.) The extreme end of :the low-pressure cylinder 2@ is also.

'Figure 3 the valve is shown closed. This might be brought about by a break in the line at A or an excessive pressure in the line A causing the pop valve to open at B or by a man-ual opening of the bleed-er valve at C.

Figure 4 illustrates how the valve may be reopened manually oy changing the position of the three-way valve l il so as to connect the control vline iid from the low-pressure cylinder through Vthe control line lil to the high-pressure control line HB6. After the valve has been reopened, the

ythree-way valve IH is returned' to the position shown in VFigure 2 to render the system Yresponsive. Y

If desired the three-way valve H! and the manual valve H can be combined into a single vfour-way valve ll i iA shown in Figure 5. As :shown the valve is in normal position connecting line Il@ to pop valve controlled exhaust line i l2. `Turning the valve to the right as shown in Figure 6 connects line il@ to atmospheric bleed line UGA to manually close the main valve while keeping the high-pressure line Hl' shut 01T. At the same time the connection to the pop valve :controlled line H2 preferably stays open to insure that the gauge pressure drops to atmospheric to show that the valve is closed. Turning the valve to the left as shown in Figure 'l connects line H0 to high-pressure line lll to manually open the valve while shutting ofi the pop valve controlled exhaust line I I2 and the atmospheric bleed line i MA.

lli/'hen a well is rst brought in it may be desired to use an adjustable choke to determine the size choke needed for a given flow. The adjustable choke may comprise a manually operated valve disposed in the valve body 2 replacing the automatic valve shown in Figure l. After the desired size choke has been determined, the proper size flow bean may be placed in the positive choke i d3 shown in Figures 2, 3 and 4. Then, with the master valve iii! still shut oii, the fast coupling il between the valve body 2 and the adjustable choke valve can be released, the adjustable choke valve replaced with the automatic valve, and the fast coupling replaced as shown in. Figure l. Thereafter reopening the master valve lili will place the system into production.

Vi/hile a preferred embodiment oi the invention has been illustrated and described, it is obvious that many modifications thereof could be made by one skilled in the art without departing from the spirit of the invention. It is desired to protect by Letters Patent all forms of the invention falling Within the scope of the appended claims.

I claim:

l. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said pasclosing means :for moving the valve member to closed position including an expansible chamber having a movable wall, opening means for moving said valve member' to open position comprising an expansible chamber having a movable wall, the nrst said wall being oi smaller area than the second said wall, means associating the two said walls and said valve member to cause movement of each of the three to at least tend to move at least one of the others with the movement of each wall upon expansion oi the chamber ci which it a part opposing like movement of the other wall, means for connecting the iirst said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side of said choke, exhaust means for connecting the second said chamber to the atmosphere, pressure responsive valve means in said exhaust means normally closing the exhaust means but adapted to open the exhaust means on increase in pressure above a predetermined amount, and three-way valve means disposed in said exhaust means between the second said chamber and said pressure responsive valve S5 means and also connnected to said pipe line on the upstream side of said valve member, said three-Way valve means in one position opening the connection in said exhaust means from the second said chamber to said pressure responsive valve means and in another position closing the last said connection and completing a through passage from the last said pipe line connection to the second said chamber.

2. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said passage, closing means for moving the valve member to closed position including an expansible chamber having a movable wall, opening means for moving said valve member to open position comprising an eapansible chamber having a movable wall, the nrst said wall being of smaller area than the second said wall, means associating the tivo said walls and said valve member to cause movement of each oi the three to at least tend to move at least one of the others with the movement of each Wall upon expansion of the chamber of which it is a part opposing like movement of the other wall, means for connecting the rst said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side of said choice, relief means icr connecting the second said chamber to atmosphere, and auxiliary valve means in said relief means interlocked with said movable wall of the second said chamber, said auxiliary valve means closing said relief means when the last said movable wall is in position corresponding to open position oi said valve member and opening said relief means when the last said movable wall has moved away from its last said position.

3. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said passage, closing means for moving the Valve member to closed position including an expansible chamber having a movable wall, opening means for moving said valve member to open position comprising an expansible chamber having a movable wall, the first said wall being oi smaller area than the second said wall, means associating the two said walls and said valve member to cause movement of each of the three to at least tend to move at least one of the others with the movement of each Wall upon expansion of the chamber of which it is a part opposing like movement of the other wall, means for connecting the :First said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side of said choke, relief means for connecting the second said chamber to atmosphere, auxiliary valve means in said relief means interloeked with said movable Wall or the second said chamber, said auxiliary valve means closing said relief means when the last said movable wall is in position corresponding to open position of said valve member and opening said relief means when the last said movable wall has moved awa-y from its last said position, land a pressure responsive devalve member adapted to beplaced ina hollow valvebody having, an inlet and anoutlet connected in a pipe line on the high-pressure side ofarchoke, said'valvemember being adapted in one position to close the passage through said body and inl another position to open said passage,

closing means for moving the valve member to closed position including an expansible chamber having adm ovable wall, opening lmeans for moving said valve member to open position comprising an expansible chamber vhaving a movable wall, the rst 'said wall being of smaller area than the second said wall, means associating the `two said walls and said valve member to cause movement of each of the three to at least tend to move at least one of the others with the movement of each wall upon expansion of the chamber of which it is a part opposing like movement of the other Wall, means for connecting the first said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side of said choke, and secondary valve means controlling the last said means closing the connection when the movable wall of the second said chamber is in position corresponding to closed position of said valve member and opening the connection when the last said wall has moved away from its last said position.

5. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said passage, closing means for moving the valve member to closed position including an expansible chamber having a movable wall, opening means forV moving said valve member to open position comprising an expansible chamber having a` movable wall, the first said wall being of rsmaller area than the second said wall, means associating the two said walls and said valve member to cause movement of each of the three to at least tend to move at least one of the others with the movement or" each wall upon expansion of the chamber of which it is a `part opposing like movement of the other wall, means for connecting the first said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side of said choke, secondary valve means controlling the last said means closing the connection when the movable wall of the second said chamber is in position corresponding to closed position of said valve member and opening the connection when the last said wall has moved away from its last said position, relief means for connecting the second said chamber to atmosphere, and auxiliary valve means disposed in said relief means interlocked with said movable wall of the second said chamber, said auxiliary valve means closing said relief means when thelast said movable wall is in position corresponding to open position of said Valve member andV opening said relief means when the last said movable wall has moved away from the last saidr position, said auxiliary valve means opening said relief means upon movement of said wall of the second chamber toward the position corresponding to closed position of4 said valve member before said secondary valve means closes said means connecting said chamber to the pipe line.

6. A pressure control apparatus comprising a Valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said passage, closing means for moving the valve member to closed position including an expansible chamber having a movable wall, opening means for moving valve member to open position comprising an expansibie chamber having a movable wall, the first said wallbeing of smaller areay than the second said wall, means associating the two said walls and said valve member to' cause movement of each' o1" the three'to at least tend to move at least one o the others with the movement of each wail upon expansion oi' the chamber of which it is a part opposing like movement of the 'other wall, means for connecting the first said chamber to said pipeline on the upstream side of said valve member, means for connecting the seoond said chamber to the pipe line on'the downstream side of said choke, the last said means including a choke, exhaust means for connecting the second said chamber to the atmosphere, and pressure responsive valve means in said exhaust means normally closing the exhaust means but adapted to open the'exhaust means on increase in pressure above a predetermined amount.

7. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said passage, closing means for moving the valve member to closed position including an expansible chamber having a movable wall, opening means for moving said valve member to open position comprising an expansible chamber having a movable wall, the rst said wall being of smaller area than the second said wall, means associating the two said walls and said valve member to cause movement of each of the three to atleast tend to move at least one of the others with the movement of each wall uponv expansion of the chamber of which it is a part opposing like movement oi the other wall, means for connecting the rst said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side or said choke, relief means for connecting the second said chamber to atmosphere, auxiliary valve means in said relief means interlooked with said movable wall of the second said chamber, said auxiliary valve means closing said relief means when the last said movable wall is in position corresponding to open position of said valve member and opening said relief means when the last said movable wall has moved away from its last said position, exhaust means for connecting the second said chamber to the atmosphere, pressure responsive valve means in said exhaust means normally closing the exhaust means but adapted to open the exhaust means on increase in pressure above a predetermined amount, and three-Way valve means disposed in said exhaust lmeans between the second said chamber and said pressure responsive valve means and also connected "to said pipe line on the upstream side of said valve member, said 1l three-way valve means in one position opening the connection in said exhaust means from the second said chamber tosaid pressure responsive valve means and in another position closing the last said connection and completing a through passage from the last said pipe line connection to the second said chamber.

8. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said passage, closing means for moving the valve member to closed position including an expansible chamber having a movable wall, opening means for moving said valve member to open position comprising an eXpansible chamber having a movable wall, the first said wall being of smaller area than the second said wall, means associating the two said walls and said valve member to cause movement of each of the three to at least tend to move at least one of the others with the movement of each wall upon expansion of the chamber or" which it is a part opposing like movement of the other wall, means for connecting the first said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side of said choke, the last said means including a choke, secondary valve means controlling the last said means closing the connection when the movable wall of the second said chamber is in position corresponding to closed position of said valve member and opening the connection when the last said wall has moved away from its last said position, relief means for connecting the second said chamber to atmosphere, auxiliary valve means in said relief means interloclred with said movable wall of the second said chamber, said auxiliary valve means closing said relief means when the last said mov-able wall is in position corresponding to open position of said valve member and opening said reliei means when the last said movable wall has moved away from its last said position, exhaust means for connecting the second said chamber to the atmosphere, pressure responsive valve means in said exhaust means normally closing the exhaust lmeans but adapted to open the exhaust means on increase in pressure above a predetermined amount, and three-Way valve means disposed in said exhaust means between the second said chamber and said pressure responsive valve means and also connected to said pipe line on the upstream side of said valve member said three-way valve means in one position opening the connection in said exhaust means from the second said chamber to said pressure responsive valve means and in another position closing the last said connection and completing a through passage rom the last said pipe line connection to the second said chamber.

9. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said passage, a valve stem connected to said valve member, closing means for moving the valve member to closed position including a cylinder of small cross-sectional area and a piston slidable axially therein,

CTL

l2 opening means for moving the valve means to open position comprising a cylinder of large crosssectional area rand a piston slidable axially therein, said piston being associated with each other and said valve stem with their axes parallel so that said opening means opposes said closing means with respect to control `of the position of the valve means, means for connecting the operating space in the small-area cylinder to said pipe line on the upstream side of said valve member, and means for connecting the operating space in the large-area cylinder to the pipe line on the downstream side of said choke, the last said means including a port in the wall of the large area cylinder, said port being closed by the piston in the large-area cylinder when the last said piston moves away from its position corresponding to full opening of the valve member.

lO. A pressure control apparatus adapted to be connected to a valve body having an inlet and an outlet comprising a valve member adapted to be placed in said body to control the flow of fluid therethrough, a valve stem connected atl one end to said valve member, a valve bonnet providing a sealing sliding support for said valve stem, a irst cylinder connected to said valve bonnet, a nrst piston on the other end of said valve stem slidably disposed in said cylinder, a second cylinder of smaller diameter than the first cylinder connected to said first cylinder, a second piston connected to the said nrst piston and slidably disposed in said second cylinder, a passage through said valve stem and pistons adapted to connect the second cylinder with the interior of said valve body, and a port through the wall of the first cylinder closed by the first piston when said valve member is in valve closing position and open when said valve member is in valve opening position.

ll. A pressure control apparatus adapted to be connected to a valve body having an inlet and an outlet comprising a valve member adapted to be placed in said body to control the ilow of iluid therethrough, a valve stem connected at one end to said valve member, a valve bonnet providing a sealing sliding support for said valve stem, said support comprising two spaced seals and an anannular chamber therebetween around said stem, a passage through said bonnet connecting said chamber to the atmosphere, a rst cylinder connected to said valve bonnet, a rst piston on the other end of said valve stem slidably disposed in said cylinder, a second cylinder of smaller diameter than the first cylinder connected to said first cylinder, a second piston connected to the first said piston and slidably disposed in said second cylinder, a passage -aapted to connect the secon cylinder with the interior of said valve body, a second passage through said valve stein for connecting the rst cylinder with said annular chamber when said valve member has moved away from full open position, said second passage being blocked off by said bonnet when said valve member is in full open position, and a port through the wall of the first cylinder closed by the first piston when said valve member is in valve closing position and open when said valve member is in valve opening position.

12. A pressure control apparatus adapted to be connected to a valve body having an inlet and an outlet comprising a valve member adapted to be placed in said body to control the flow of fluid therethrough, a valve stem connected at one end to said valve member, a valve bonnet providing a sealing sliding support for said valve stem, said support comprising two spaced seals and an annular chamber therebetween around said stem, a passage through said bonnet connecting said chamber to the atmosphere, a first cylinder connected to said valve bonnet, a nrst piston on the other end or" said valve stern slidably disposed in said cylinder, a second cylinder of smaller diameter than the iirst cylinder connected to said rst cylinder, a second piston connected to the nrst said piston and slidably disposed in said second cylinder, a passage through said valve stem and pistons adapted to connect the Second cylinder with the interior of said valve body, a second passage through saidy valve stem for connecting the nrst cylinder with said annular chamber when said valve member has moved away from full open position, said second passage being blocked ci by said bonnet when said valve member is in full open position, and a port through the wall of the first cylinder closed by the first piston when said valve member is in valve closing position and open when said valve member is in valve opening position.

13. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in ano-ther position to open said passage, closing means for moving the valve member to closed position including an expansible chamber having a movable wall, opening means for moving said valve member to open position comprising an expansible chamber having a movable wall, the rst said wall being of smaller area than the second said wall, means associating the two said walls and said valve member to cause movement of each of the three to at least tend to move at least one of the others with the movement of each Wall upon expansion of the chamber of which it is a part opposing like movement of the other wall, means for connecting the irst said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side of said choke, exhaust means for connecting the second said chamber to the atmosphere, pressure responsive valve means in said exhaust means normally closing the exhaust means but adapted to open the exhaust means on increase in pressure above a predetermined amount, and four-way valve means disposed in said exhaust means 4between the second said chamber and said pressure responsive valve means and also connected to said pipe line on the upstream side of said valve member and further connected to an exhaust line, said four-way valve means in one position opening the connection in said exhaust means vfrom the second said chamber to said pressure responsive valve means while closing the last said pipe line connection and exhaust line and in another position connecting the second said chamber to the last said pipe line connection while closing the exhaust means and exhaust line, and in still another position connecting the second said chamber to the exhaust line while closing the last said pipe line connection.

14. A pressure'control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body 14. and in another position to open said passage, closing means for moving the valve member to closed position including an expansible chamber having a movable wall, opening means for moving said valve member to open position comprising an expansible chamber having a movable wall, the rst said wall being of smaller area than the second said wall, means associating the two said walls and said valve member to cause movement of each or" the three to at least tend to move at least one of the others with the movement of each wall upon expansion of the chamber of which it is a part opposing like movement or" the other wall, means for connecting the rst said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side of said choke, the last said means including a choke, secondary valve means contro-lling the last said means closing the connection when the movable wall of the second said chamber is in position corresponding to closed position of said valve member and opening the connection when the last said wall has moved away from its last said position, relief means for connecting the second said chamber to atmosphere, auxiliary valve means in said relief means interlocked with said movable wall of the second said chamber, said auxiliary valve means closing said relief means when the last said movable wall is in position corresponding to open position of said valve nember and opening said relief means when the last said movable wall has moved away from its last said position, exhaust means for connecting the second said chamber to the atmosphere, pressure responsive valve means in said exhaust means normally closing the exhaust means but adapted to open the exhaust means on increase in pressure above a predetermined amount, manual valve means in said exhaust means ior opening the exhaust line when desired, a pressure responsive device connected to said exhaust means upstream from said pressure responsive valve means to indicate the position of said valve member, and three-way valve means disposed in said exhaust means between the second said chamber and said pressure responsive valve means and also Connected to said pipe line on the upstream side of said valve member, said three-way valve means in one position opening the connection in said exhaust means from the second said chamber to said pressure responsive valve means and in another position closing the last said connection and completing a through passage from the last said pipe line connection to the second said chamber.

l5. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said passage, closing means for moving the valve member to closed position including an expansible chamber having a movable wall, opening means for moving said valve member to open position comprising an expansible chamber having a movable wall, the rst said wall being oi smaller area than the second said wall, means associating the two said walls and said valve member to cause movement of each of the three to at least tend to move at least one of the others with the movement of each wall upon expansion of the chamber of which itis a part opposing like movement of the other wall, means for connecting the irst said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line on the downstream side of said choke, the last said means including a choke, secondary valve means controlling the last said means closing the connection when the movable wall of the second said chamber is in position corresponding to closed position of said valve member and opening the connection when the last said Wall has moved away from its last said position, relief means for connecting the second said chamber to atmosphere, auxiliary valve means in said relief means interlocked with said movable wall of the second said chamber, said auxiliary valve means closing said relief means when the last said movable wall is in position corresponding to open position of said valve member and opening said relief means when the last said movable wall has moved away from its last said position, exhaust means for connecting the second said chamber to the atmosphere, pressure responsive valve means in said exhaust means normally closing the exhaust means but adapted to open the exhaust means on increase in pressure above a predetermined amount, and four-way valve means disposed in said exhaust means between the second said chamber and said pressure responsive valve means and also connected to said pipe line on the upstream side of said valve member and further connected to an exhaust line, said four-way valve means in one position opening' the connection in said exhaust means from the second said chamber to said pressure responsive valve means while closing the last said pipe line connection and exhaust line and in another position connecting the second said chamber to the last said pipe line connection while closing the exhaust means and exhaust line, and in still another position connecting the second said chamber to the exhaust line while closing the last said pipe line connection.

16. A pressure control apparatus comprising a valve member adapted to be placed in a hollow valve body having an inlet and an outlet connected in a pipe line on the high-pressure side of a choke, said valve member being adapted in one position to close the passage through said body and in another position to open said passage, closing means for moving the valve member to closed position including an expansible chamber having a movable wall, opening means for moving said valve member to open position comprising an expansible chamber having a movable wall, the rst said Wall being of smaller area than the second said wall, means associating the two said walls and said valve member to cause movement of each of the three to at least tend to move at least one of the others with the movement of each wall upon expansion of the chamber of which it is a part opposing like movement of the other wall, means for connecting the rst said chamber to said pipe line on the upstream side of said valve member, means for connecting the second said chamber to the pipe line en the downstream side of said choke, the last said means including a choke, secondary valve means controlling the last said means closing the connection when the movable wall of the second said chamber is in position corresponding to closed position of said valve member and opening the connection when the last said wall has moved away from its last said position, relief means for connecting the second said chamber to atmosphere, auxiliary valve means in said relief means interlocked with said movable wall of the second said chamber, said auxiliary valve means closing said relief means when the last said movable wall is in position corresponding to open position of said valve member and opening said relief means When the last said movable wall has moved away from its last said position, exhaust means for connecting the second said chamber to the atmosphere, pressure responsive valve means in said exhaust means normally closing the exhaust means but adapted to open the exhaust means on increase in pressure above a predetermined amount, a pressure responsive device connected to said exhaust means upstream from said pressure responsive valve means to indicate the position of said valve member, and four-way valve means disposed in said exhaust means between the second said chamber and said pressure responsive valve means and also connected to said pipe line on the upstream side of said valve member and further connected to an exhaust line, said four-way valve means in one position opening the connection in said exhaust means from the second said chamber to said pressure responsive valve means while closing the last said pipe line connection and exhaust line and in another position connecting the second said chamber to the last said pipe line connection while closing the exhaust means and exhaust line, and in still another position connecting the second said chamber to the exhaust line and exhaust means while closing the last said pipe line connection.

17. In apparatus including a pipe line, a valve body in the pipe line having an inlet connected to the upstream side of the line and an outlet connected to the downstream side of the line, the improvement comprising a valve member in said valve body, means responsive to upstream pressure to close the valve, said valve closing means comprising an expansible chamber having a movable wall, said chamber being connected to means to vary the pressure therein in accordance with changes in the upstream pressure in said line, means responsive to downstream pressure to open the valve, said valve opening means comprising an expansible chamber having a movable wall of larger effective area than the first said wall, the second said chamber being connected to means to vary the pressure therein in accordance with changes in the downstream pressure in said line, means associating said tvvo walls and valve member to cause movement oi any one of the three to at least tend to move at least one of the others and with the movement of each wall upon expansion of the chamber of which it is a part opposing like movement of the other wall, and means responsive to increase or" downstream pressure to lower the pressure in the second said chamber below normal downstream pressure.

i8. A pressure control apparatus comprising a valve member adapted to be placed in a valve body having an inlet and an outlet to control the passage of fluid therethrough, means to move the valve member to closed position including an expansible chamber having a movable wall, means to move the valve member to open position including an expansible chamber having a movable wall of larger eiective area than the rst said wall, means associating the two said walls and said valve member to cause movement of any one of the three to at least tend to move at least one of the others and with the movement of each wall upon expansion of the chamassai-ess ber vofwhich it is-apart-opposing likemovement chamber toa sourceof pressure, means-tocchn'ect the -second vsaid chamber vto Ya source of lower 'pressure,'m'eans responsive to 'closing movement of' saidvalve member to close oirsa-id means to connectr the second sai-d chamber f to a source of lowerpressure, and means responsiveto closing'movement or saidvalvemeinber to open said second chamber to atmosphere.

l'19; A pressurecontrolv apparatus comprising ya valve member adaptedl tobe placedin a'valve bodyhaving'an inlet andra-n*outlet to control the passage of-iiuid ther'ethrough,` mean-sto move-the valve Ymember to vclosed position including van expansible chamber having a movable wall, means to Amove the valve member to f open position includingf an expansibi'e chamber having Aa, movablewall of larger'eiectivef-*area than` the iirst said 'wail I means f' associating the-v two said vwallsandsaid valve member to` cause movement of anyone-y of the-three to-atieast`tendI to move -at least one of theV others Iand* with the'movement or each ,vallvuponexpansion of the chamber of which it is Aa part1 opposingl likel movement ofthe other-wall; means to connectthe iirst saidv chamberto a source of pressure,` meansto 'connect-the second said-chamber to-a1souroe of lower-pressure,1means responsive toincreasecf pressure in said. second chamber rto opensaidlseoon'd chamber-Lto a space of Vstill lower pressure thanthe said :lower pressure, and vmeans responsive to closing. movement of said-valve men'iber to` close oilisaid'm'ean's to connect the .secondv saidy chamberfto asource `oflower pressure.

:20; Azpressurez control "apparatus :comprisinga valvexmember adapted to be placed in :a valve body;havingfarrl inlet and-an. outlet to .control the passage of L iiuid a therethrough,.. a valve stem l.connested;l to said valve memben closing `.means for moving the. valvefmemher tofclosedposition including arcylinder of smallfcross-'sectional area and7 aipiston slidable axially therein, .opening means for moving the;v valveV member .to open.

position comprising'` a :cylinder .or largeV cross-:setonal area and a piston slidable axially therein, saidpistons being associated with each other and said valvefstemrW-ith'their vaxesvparallel so that said opening means opposes said closing.

means-'with respect to control of the positionof they ValVememher; means' forconn'ecting theoperating *space in the `smalle'airea cylinder to "a source of pressure, meansfor connecting the operating space `in-the-large-area vcylinder to a source oflowerpressureyrelief means for' con-y necting the operating spa-ce in the large-area cylinder to atmosphere;I said relief' means includingfa, channelV throughthestem of the piston in thelloW- pressure'cylinder, yone-end oi saidchannel' nearest' thehead of the piston'alwayscommunicating'with the operating space in the largearea cylinder, and means cooperating with the other end of the channel to close said channel when sai'clpiston in the low-pressure cylinder is in a positioncorresp'onding to full opening of the valve member.

21.In apparatusforcontrolling-ai'iow of iluid through.. a conduit, said-apparatus comprising .la valverbocly-'having a flow passage therethrough connected into saidconduitto form therewith a continuous now line, said valve bodyhaving an opening therein extending from the exterior thereof into said flow passage, and a choke in said line to cause a drop in the pressure of fluid flowing through the line from a higher pressure on the upstream side of said apparatus to a lower 18" pressure' on thedownstreainV side oft-said apparatus, the improvement comprising a valvemember adapted'to-'be positioned inl-said valve body-V in one position to'l cl'osethe passage therethrough andfn another-position to opensaid passage, -a'- valve 1 bonnet adaptedl t'o close saidvalVe'Openin'g, means tolseal said bonnet' to -said valvebod'y, lsaid bonnet havinga stem opening therethrough, fa. valve stem passing through said stem-opening."

l0 and movable thereinand yconnected tosaid valve`- member,.means to seal lietweensaid.stemfaniisaid stem opening, means toumove saidi-v-alv'e'- member to closed*positionincluding a cylinder and apiston siidable axially'thereim meansfftul move said valvememberflto open position comiprising ac3-vlinder .offla'rger diameter 'thanfthel rst saidv cylinder'andiia, .piston slidable axiallytherein, means connecting said' pistons. 'tir.sail. valve stem,.meansfto\connect' one-part oftherstl expose oneiside Vofssaid piston therein .tofsai'trv higher pressure; means. to z connect-.another part: of the first said-:cylinder to atmosphere to :confstantly expose the kotherI side ofsaid piston there-- in to atmospheric presure,zmeans to 'connect-one valve bodyymeanszresponsive to upstream pres-- sure-to close thevalve, said'valve closing meansl :4oficomprising an expansiblech amber havingca. movable wall, said chamber-being connected to mea-ns: to vary theA pressure therein. in accordancefwith.- changes in theupstreama-pressure insaidfline;l means responsive to downstream pressure to open; the valve, said valve opening meanscomprisingl; an expansiblefchamber having ra-.movalole"wall of larger effective area thanA the first saidwall.. the second saidt chamber .being-connected .to means kto vary the: pressure'therein'inaccordance` with changes inthev downstream pressure insaid line, means associating-,said-.twowalls and rvalvel member to cause'movement ofany one.' ofthe.- three to :at least tendfto move at leastv one-ofthe others and with-themovement; of each wallupon expansionof the chambero-which it is a part. opposing likeI movement of; the: other wall, reliefT means connecting said :second expansible chamber to a source-of. pressure lower than-said-downstream pressure, auxiliary valve. means insa-id relief means to control lowvthrough saidreliefy means, meansto oausesaid auxiliary valve means to be closed-when said-valve member is-in` its-full.- open position and to cause said auxiliary valve..` means to` open when: said-.valve member `moves; toward open position 23. In apparatus-for..controlling new` of vfluid through a lconduit,.said apparatusl confiprising-a` valve body having a*flow-passagertherethrough connected into said conduit'to formtherewith a'. continuous ow line, -said valve .body having 'an' opening therein extending. from the exterior thereof into said flow passage, and a choke in said line to cause a drop in the pressure of iiuid owing through the line from a Ihigher pressure on the upstream side of said apparatus to a lower 7 pressure on the downstream side of said apparatus, the improvement comprising a valve member adapted to be positioned in said valve body in one position to close the passage therethrough and in another position to open said passage, a valve bonnet adapted to close said valve opening, means to seal said bonnet to said valve body, said bonnet having a stem opening therethrough, a valve steam passing through said stem opening and movable therein and connected to said valve member, means to seal between said stem and said stem opening, means to move the valve member to closed position including an expansible chamber having a movable wall, means to move the valve member to open position including an expansible chamber having a movable wall of largei` eective area than the first said wall, means associating the two said walls and said valve stem to cause movement of any one of the three to at least tend to move at least one of the others and with the movement oi each wall upon expansion of the chamber of which it is a part opposing like movement of the other wall, means to connect the exterior surface of each of said movable walls, that is, the surface outside of the respective chamber, to atmosphere at all times, means to connect the iirst said chamber to the upstream of said line, means to connect the second said chamber to the downstream part or said line, and means responsive to closing movement of said valve member to close off said means to connect the second chamber to the downstream part of said line.

24, A pressure control apparatus comprising a valve member adapted to be placed in a valve body having an inlet and an outlet to control the passage of fluid therethrough, means to move the valve member to closed position including an expansible chamber having a movable wall, means to move the valve member to open position including an expansible chamber having a movable wall of larger effective area than the rst said Wall, means associating the two said walls and said valve member to cause movement of any one of the three to at least tend to move at least one of the others and with the movement of each wall upon expansion of the chamber of which it is a part opposing like movement of the other wall, means to connect the iirst said chamber to a source of pressure, means to connect the Second said chamber to a source of lower pressure, means responsive to increase of pressure in said second chamber to open said second chamber to a space of still lower pressure than the said lower pressure, and means separate from the last said means and responsive to closing movement of said valve member to rst open said second chamber to a space of still lower pressure than said lower pressure and thereafter to close oil? said means to connect the second said chamber to a source of lower pressure.

25. In apparatus for controlling now of iluid through a conduit, said apparatus comprising a valve body having a 110W passage therethrough connected into said conduit to form therewith a continuous now line, said valve body having an opening therein extending from the exterior thereof into said flow passage, and a choke in said line to cause a drop in the pressure of iiuid iiowing through the line from a higher pressure on the upstream side of said apparatus to a lower pressure on the downstream side of said apparatus, the improvement comprising a valve member adapted to be positioned in said valve body in one position to close the passage therethrough and in another position to open said passage, a valve bonnet adapted to close said valve opening, means to seal said bonnet to said valve body, said bonnet having a stem opening therethrough, a valve stem passing through said stem opening and movable therein and connected to said valve member, means to seal between said stem and said stem opening, means to move said valve member to closed position including a cylinder and a piston slidable axially therein, means to move said valve member to open position comprising a cylinder of larger diameter than the first said cylinder and a piston slidable axially therein, means connecting the second said cylinder to the valve bonnet, means integral with said second cylinder closing one end thereof, a piston rod passing through the other end of said second cylinder and connected at one end to said piston therein and at the other end to said valve stem, said rst cylinder being disposed inside second cylinder with one end of said rst cylinder abutting against said closed end of the second cylinder, means to releasably secure said first cylinder in said second cylinder, means to seal between said one end of said rst cylinder and said closed end of said second cylinder, a piston rod passing through the other end of said rst cylinder and connected at one end to said piston therein and at the other end to said piston in the second cylinder, means to connect the part of the first said cylinder on that one side of the piston therein adjacent said sealed end thereof to said upstream part of the line to expose said one side or" the piston to said higher pressure, means to connect the second said cylinder on that one side of the piston therein that is connected to the valve stem to said downstream part of the line to expose said one side of the piston therein to said lower pressure, and a port to atmosphere through the second said cylinder between the other side of the piston therein and the other side of the piston in the first cylinder.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 827,998 Schutte Aug. 7, 1906 1,167,287 Ford Jan. 4, 1916 1,209,796 Anderson Dec. 26, 1916 1,658,445 Knauf Feb. 7, 1928 2,021,773 Gentzel Nov. 19, 1935 2,043,453 Vickers June 9, 1936 2,092,452 Gilbert Sept. 7, 1937 2,227,297 Coy Dec. 31, 1940 2,280,140 Wilson Apr. 21, 1942 2,401,237 Gamble May 28, 1946 2,418,743 Baker Apr. 8, 1947 FOREGN PATENTS Number Country Date 186,910 Great Britain Oct. 5, i921 OTHER REFERENCES N. A. C. A. Report No. 206 Nonmetallic Diaphragms for Instruments by H. N. Eaton and C. T. Buckingham, Tenth Annual Report N. A. C. A. for 1924, published 1925, by G. P. O., Washington, D. C., pages 446 to 450 inclusive. 

